Round balers generally have a bale forming chamber defined by a pair of opposing side walls associated with an array of side-by-side belts, transverse slats trained on chains, a plurality of transverse rolls or a combination of these various elements, e.g., rolls and belts. During field operation, windrowed crop material such as hay is picked up from the ground and fed into a fixed or variable diameter bale forming chamber. The hay is then rolled into a cylindrical package, wrapped with twine, net or the like and ejected onto the ground for subsequent handling.
U.S. Pat. No. 5,444,969, issued Aug. 29, 1995 in the name of Robert A. Wagstaff, et al, discloses a prior art round baler of the general nature described above. In this particular type of baler an expandable chamber is defined by a pair of sidewalls, and a plurality of side-by-side belts cooperating with a plurality of transverse rolls, mounted between a pair of pivotally mounted arms. The chamber includes an inlet opening in the front through which crop material is fed. The aforementioned arrangement of rolls and arms is commonly referred to as a sledge assembly. Also shown in the disclosed baler is a pair of take up arms pivotally mounted on the main frame, between which arms a pair of guide rolls are journalled. The outer surfaces of the guide rolls are urged against the belts to maintain belt tension and thereby prevent slack from occurring in the belts during expansion and contraction of the chamber.
The present invention relates to an improved round baler in which a cylindrical package of crop material is formed between expandable walls consisting of a combination of belts and rolls of the general nature described in the preceding paragraph. The '969 patent, cited above, is an example of many prior art patents, assigned to New Holland North America, Inc., that disclose this type of round baler. More particularly, the present invention is directed to improvements to the unique structural characteristics described and claimed in the parent application referred to in the first paragraph of this application, i.e., a round baler having an expandable bale forming chamber defined in part by belts and rolls, wherein the belt take up assembly and sledge assembly operate in concert. These improvements contribute to a round baler featuring, among other things, enhanced performance and improved durability.